From 7ebfe09fbd5e8ce00ae811aea1f2d84dfc73a577 Mon Sep 17 00:00:00 2001 From: Damien George Date: Thu, 26 May 2016 17:13:03 +0100 Subject: [PATCH] esp8266: Add dht.py script for high-level control of DHT11/DHT22 sensor. TODO: should go in a more port-neutral place, like drivers/dht, but at the moment in relies on specific esp module. --- esp8266/scripts/dht.py | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) create mode 100644 esp8266/scripts/dht.py diff --git a/esp8266/scripts/dht.py b/esp8266/scripts/dht.py new file mode 100644 index 0000000000..9a69e7e07e --- /dev/null +++ b/esp8266/scripts/dht.py @@ -0,0 +1,32 @@ +# DHT11/DHT22 driver for MicroPython on ESP8266 +# MIT license; Copyright (c) 2016 Damien P. George + +import esp + +class DHTBase: + def __init__(self, pin): + self.pin = pin + self.buf = bytearray(5) + + def measure(self): + buf = self.buf + esp.dht_readinto(self.pin, buf) + if (buf[0] + buf[1] + buf[2] + buf[3]) & 0xff != buf[4]: + raise Exception("checksum error") + +class DHT11(DHTBase): + def humidity(self): + return self.buf[0] + + def temperature(self): + return self.buf[2] + +class DHT22(DHTBase): + def humidity(self): + return (self.buf[0] << 8 | self.buf[1]) * 0.1 + + def temperature(self): + t = ((self.buf[2] & 0x7f) << 8 | self.buf[3]) * 0.1 + if self.buf[2] & 0x80: + t = -t + return t